Let's get this math done. We have 3634 and 4004 and we're going to add them all together.

Step 1: We'll start by adding the digits 4 & 4 in column 1 and get 8.

Step 2: We'll start by adding the digits 3 & 0 in column 2 and get 3.

Step 3: We'll start by adding the digits 6 & 0 in column 3 and get 6.

Step 4: We'll start by adding the digits 3 & 4 in column 4 and get 7.

So, 3634 + 4004 = 7638.

